Очень хотелось бы узнать, что хочет от меня валидатор. Помогите, плиз

package com.javarush.task.task19.task1918; import java.io.*; import java.util.*; import java.util.regex.Pattern; import java.util.regex.Matcher; /* Знакомство с тегами */ public class Solution { public static void main(String[] args) throws Exception { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); String fileName = br.readLine(); br.close(); BufferedReader br1 = new BufferedReader(new FileReader(fileName)); ArrayList<String> list = new ArrayList<>(); while (true) { String s = br1.readLine(); if (s!=null) list.add(s+"\n"); else break; } br1.close(); String s1 = ""; for (String s2: list) s1 += s2; Pattern pattern = Pattern.compile("\\<"+args[0]+"\\>"); Matcher matcher = pattern.matcher(s1); Pattern pattern2 = Pattern.compile("\\<"+args[0]+" .+?\\>"); Matcher matcher2 = pattern2.matcher(s1); Pattern pattern3 = Pattern.compile("\\<"+args[0]+"\\n.+?\\>"); Matcher matcher3 = pattern3.matcher(s1); ArrayList<Integer> list1 = new ArrayList<>(); ArrayList<Integer> list2 = new ArrayList<>(); while (matcher.find()) { int start = matcher.start(); list1.add(start); } while (matcher2.find()) { int start = matcher2.start(); list1.add(start); } while (matcher3.find()) { int start = matcher3.start(); list1.add(start); } Collections.sort(list1); Pattern pattern1 = Pattern.compile("\\</"+args[0]+"\\>"); Matcher matcher1 = pattern1.matcher(s1); while (matcher1.find()) { int start = matcher1.start(); list2.add(start); } HashMap<Integer, Integer> map = new HashMap<>(); ArrayList<Integer> list3 = new ArrayList<>(list1); for (int k = 0; k <= list2.size() - 1; k++) { int min = list2.get(k); int minindex = 0; for (int i = 0; i<=list1.size() - 1; i++) { int j = list2.get(k) - list1.get(i); if (j<min&&j>=0) { min = j; minindex = i; } } map.put(list1.get(minindex), list2.get(k)); list1.remove(minindex); } for (Integer l: list3) { String s10 = s1.substring(l, map.get(l) + args[0].length() + 3); System.out.println(s10.replaceAll("\n", "")); } } }